googleapis_auth: prepare v1.5.1 release (#608)

diff --git a/googleapis_auth/CHANGELOG.md b/googleapis_auth/CHANGELOG.md
index 1dae372..d56121b 100644
--- a/googleapis_auth/CHANGELOG.md
+++ b/googleapis_auth/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.5.1
+
+- `auth_browser.dart`: handle pop-up closed errors correctly. 
+
 ## 1.5.0
 
 - Add support for non-Google OAuth 2.0 providers.
diff --git a/googleapis_auth/pubspec.yaml b/googleapis_auth/pubspec.yaml
index c51b3a7..8fce744 100644
--- a/googleapis_auth/pubspec.yaml
+++ b/googleapis_auth/pubspec.yaml
@@ -1,5 +1,5 @@
 name: googleapis_auth
-version: 1.5.0
+version: 1.5.1
 description: Obtain Access credentials for Google services using OAuth 2.0
 repository: https://github.com/google/googleapis.dart/tree/master/googleapis_auth